The measurement of effective reaction cross-sections for 74Be
production by irradiation of light nuclei (C, O, F, Na, Cl, K) with fast neutrons from the
interaction of 660 MeV protons with a thick lead target is described. The experiment was
conducted on the proton accelerator at the Nuclear Problems Laboratory (JINR, Dubna).
Measurements of the neutron flux density and the 74Be production rate were performed
using the activation method. Cross-sections of 74Be production decrease from 0.01 barns
for carbon to 0.00005 barns for potassium. The model of nuclear reactions of ~20-50 MeV
neutrons with light nuclei taking into account the effective potential barrier for 74Be was
used. In general, the model correctly reproduces the measured values.